The current state of health of the United States, including physical inactivity, dietary intake, and overall lifestyle habits is of concern for educators. Specifically, the health of the college population appears to be under-represented in health and wellness research. The purpose of this study was to evaluate a 15-week university wellness-based…

Classic parametric statistical significance tests, such as analysis of variance and least squares regression, are widely used by researchers in many disciplines, including psychology. For classic parametric tests to produce accurate results, the assumptions underlying them (e.g., normality and homoscedasticity) must be satisfied. These assumptions…

This article familiarizes readers with how to analyze personnel selection decisions in employment discrimination litigation. First, the authors outline some of the basic legal principles that serve as the basis for analyses related to claims of discriminatory employment practices. Second, they describe how to conduct a scientific investigation of…

Examination of the literature on statistics indicates that the rejection of the hypothesis of chance dates from the turn of the century. Early statements about statistical significance were given in terms of the "probable error." These earlier conventions were adopted and restated by Fisher in his "Statistical Methods for Research…

A procedure is discussed for testing the significance of the difference in two correlated correlation coefficients, using Fisher's Z-Transformation. The procedure is applicable to a wide range of problems involving tests between dependent correlations and has documented mathematical support when its power curves are examined. (MH)

Explains that an initial criterion to determine severe discrepancies and relative strengths and weaknesses is significant difference between regressed standard scores. Presents tables as convenient method to determine magnitude of discrepancy required for significance at common reliability and intercorrelation values. Shows prevalences of…

Curriculum materials designed to provide students with practice interpreting plotted evidence of global climate change were developed using graphs from the scientific literature and tested with one hundred urban high school students from a high-poverty school in a major northern city in the US. The graph interpretation lessons followed a…

A common mistake in analysis of cluster randomized trials is to ignore the effect of clustering and analyze the data as if each treatment group were a simple random sample. This typically leads to an overstatement of the precision of results and anticonservative conclusions about precision and statistical significance of treatment effects. This…

An empirical sampling study investigated six procedures for testing differences between means in the presence of unequal n's and variances. Support was obtained for previous research which found t robust to heterogeneous variances only when n's are equal and of moderate size. The procedure which emerged as providing the best control over Type I…

This study investigated the effects of non-normality of the marginal distributions of the bivariate surface upon the sampling distribution of certain tests of significance of differences for the product moment correlation coefficient. The effects of non-normality were found to be rather substantial and to be dependent upon: 1) the degree of…

Various cases of unequal variances and unequal sample sizes from a normal and a skewed population were used to empirically obtain the probability of a Type I error and the power for the permutation t-test as compared to Student's t-test and the Mann-Whitney U-test. Empirical results showed differences for different sample sizes, variance ratios,…

A general method of devising stepwise multiple testing procedures with fixed experimentwise error is applied to the problem of non-parametric randomized block design with ordered alternatives. In addition, the method is applied to other models with ordered alternatives. (Author)